/// 水波纹下划线
@mixin waveUnderLine($color: red) {
  &:hover {
    color: $color;
    text-decoration: none;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 20 4'%3E%3Cpath fill='none' stroke='%23ff3300' d='M0 3.5c5 0 5-3 10-3s5 3 10 3 5-3 10-3 5 3 10 3'/%3E%3C/svg%3E")
      repeat-x 0 100%;
    background-size: 20px auto;
    animation: wave 1s linear infinite;
  }
}
@keyframes wave {
  from {
    background-position-x: 0;
  }
  to {
    background-position-x: -20px;
  }
}
